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Preparation technology of cyclopentadiene or substituted cyclo pentadiene

A technology of cyclopentadiene and cyclopentenol, which is applied in the field of preparation technology of tetramethylcyclopentadiene, can solve the problems of difficult separation of reaction mixture and failure to reflect the actual yield of the target product, and achieve the goal of simplifying the process flow Effect

Inactive Publication Date: 2006-12-27
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The shortcoming of this method is: the ratio of trisubstituted and tetrasubstituted cyclopentadiene reaches 35:65 in the reaction mixture, and the separation of reaction mixture is more difficult
Therefore, it cannot reflect the actual yield of the target product in the whole process

Method used

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  • Preparation technology of cyclopentadiene or substituted cyclo pentadiene
  • Preparation technology of cyclopentadiene or substituted cyclo pentadiene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] After the reaction bottle has been fully inertly replaced, add 250ml of 1 ether and 17g of lithium aluminum tetrahydride in sequence, start stirring, and cool the mixture to 0°C. Under continuous stirring, add 45g (0.29mol) of Hydrogen-2,3,5,6 tetramethyl-γ-pyrone was slowly added dropwise into the reaction flask. After the addition, continue to stir for 0.5 hours, slowly raise the temperature to 25° C. and stir for 3 hours, slowly add acidic distilled water with pH=2 for hydrolysis. Then add 200ml of benzene and 62.8g of p-toluenesulfonic acid, and reflux for 12 hours in a boiling state to stop the reaction. The liquid in the reaction mixture was separated by decantation, the remaining solid was washed twice with ether and the washing liquid was mixed with the liquid obtained by decantation, neutralized to neutral with saturated sodium carbonate solution, the organic layer was washed twice with water, anhydrous magnesium sulfate Drying, filtration removes magnesium su...

Embodiment 2

[0027] After the reaction flask has been fully inertly replaced, add 1g of a mixture consisting of ferric chloride (0.2g) and copper chloride (0.8g), 250ml of 1 ether and 17g of lithium aluminum hydride in sequence, start stirring, and cool the mixture to 0 °C, under continuous stirring, slowly drop 45g (0.29mol) of 2,3,5,6-tetrahydro-2,3,5,6 tetramethyl-γ-pyrone into the reaction flask. The following steps are the same as in Example 1 to obtain 23.4 g of 1,2,3,4-tetramethylcyclopentadiene, (by feeding 2,3,5,6-tetrahydro-2,3,5,6 tetramethylcyclopentadiene Based on the moles of γ-pyrone) the yield was 66%.

Embodiment 3

[0036] With glacial acetic acid as a dehydrating agent, other processes are the same as in Example 2 to obtain 22.4 g of 1,2,3,4-tetramethylcyclopentadiene (with 2,3,5,6-tetrahydro-2,3, 5,6 moles of tetramethyl-γ-pyrone), the yield was 63.4%.

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Abstract

A process for preparing the cyclopenetadiene or substituted cyclopentadiene, especially the tetramethyl cyclopentadiene, from the gamma-pyranone or substituted gamma-pyranone includes such steps as catalytic reduction under exixtance of Lewis acid, hydrolyzing and dewatering under acidic condition. It has high output rate.

Description

technical field [0001] The invention relates to a preparation process of cyclopentadiene or substituted cyclopentadiene, in particular to a preparation process of tetramethylcyclopentadiene. Background technique [0002] Cyclopentadiene or substituted cyclopentadiene is one of the most important ligands in transition metal chemistry. Cyclopentadiene, tetramethylcyclopentadiene, and pentamethylcyclopentadiene are very useful ligands in the process of preparing single-site catalysts. They can be used to prepare various metallocene compounds. These compounds are in In the presence of methylaluminoxane (MAO), it is an excellent catalyst for the production of polyolefins such as polyethylene and polypropylene. In addition, cyclopentadiene is used as a polymerized monomer or comonomer for the preparation of polycyclopentadiene. [0003] Cyclopentadiene or substituted cyclopentadiene is difficult to obtain. A small amount of cyclopentadiene and methylcyclopentadiene can be crack...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C13/15C07C1/20C07C1/22C07C1/24C07C1/207
Inventor 韦少义朱博超吴江魏红郝萍
Owner PETROCHINA CO LTD